Multi axle, self-loading heavy load transporters may experience problems with getting the deck of the transporter to lower uniformly when disengaging from under a load platform. Typically, the transporter is lowered to drive under stand-supported loads. The vertical entry clearance is minimal and the leading edge of the transporter must be as low as possible. Often, the unloaded weight of the transporter's load deck is only marginally sufficient to overcome cylinder resistance (e.g. the fluid resistance from the hydraulic fluid within the cylinder and the friction between moving components of the cylinder including the piston rod) and the resistance of the hydraulic fluid as it flows back to the reservoir. For example, the end(s) of the transporter load deck that are the farthest from the hydraulic fluid reservoir may experience increased resistance when lowering under gravity due to the fluid resistance of the lengthy hydraulic fluid lines. In a best case scenario, the resistance causes the load deck to be slow reacting, while in the worst case scenario, the transporter deck does not fully lower and cannot be positioned beneath a load. One proposed solution to cause the load deck to lower evenly requires the use weights and counterweights placed on the load deck; however, this has proven largely impractical.
There exists a need for a highly maneuverable transporter capable of efficiently hydraulically raising and lowering the transporter load deck during self-loading operations. In addition, there exists a need for an axle assembly where the rotation of the axle assembly can be monitored when one or more axle hydraulic cylinders are in any portion of stroke in any portion of extended and retracted orientation.